Method for manufacturing liner body for combustion chambers and liner produced by the method

ABSTRACT

A liner body for combination chambers comprises a cover plate made entirely of welding material deposited across the ends of and united with a plurality of parallel spaced cooling elements such as cooling fins. The cooling fins are held in proper parallel relation by a jig and the welding material is deposited across the end faces of the fins in one or more layers.

United States Patent Kuhnen [4 Oct. 24, 1972 [54] METHOD FORMANUFACTURING LINER BODY FOR COMBUSTION CHAMBERS AND LINER PRODUCED BYTHE METHOD [72] Inventor: Gottfried Kuhnen, Nussbaumen,

Switzerland [73] Assignee: Aktiengesellschaft Brown, Boveri &

Cie, Baden, Switzerland [30] Foreign Application Priority Data April 30,1968 Switzerland ..6451/68 [52] US. Cl. ..29/493, 29/471.l, 29/1573 R,

165/181 [51] Int. Cl. ..B23k 5/22 as v V V =4 72' [58] Field of Search..165/18*0; 263/42; 29/471.1, I 29/4713, 472.1, 493

[5 6] References Cited UNITED STATES PATENTS 1,510,146 9/ 1924 Johnson..29/493 X 3,306,642 2/ 1967 Arnold et al ..29/471.1 3,028,326 4/1962Brand et al. ..29/493 Primary Examiner-John J. Camby AssistantExaminerTheophil W. Streule Attorney-Pierce, Scheffler & Parker [5 7]ABSTRACT A liner body for combination chambers comprises a cover platemade entirely of welding material deposited across the ends of andunited with a plurali ty of parallel spaced cooling elements such ascooling fins. The cooling tins are held in proper parallel relation by ajig and the welding material is deposited across the end faces of thefins in one or more layers.

5 Claims, 2 Drawing Figures PATENTEDnm 24 I972 .Fig. 2

Fig.1v

GoffFried kuhnen PM JWMMWA' a METHOD FOR MANUFACTURING LINER BODY FORCOMBUSTION CHAMBERS AND LINER PRODUCED BY THE METHOD This is acontinuation of Ser. No. 820,270 filed Apr. 29, 1969, now abandoned.

This invention relates to a method for the manufacture of a liner bodyfor combustion chambers which has, at its side facing the combustionarea, a cover plate and, at its reverse side, cooling elements, and italso relates to a liner body produced by this method.

Metallic combustion chambers consist essentially of two coaxial,cylindrical bodies, the inner one enclosing the combustion area whilethe outer one forms the pressure resistant jacket. Tocool the innerjacket, a cooling medium, preferably air, is conducted through theannular gap between the two cylinders. The cooled,

external surface of the inner jacket is advantageously so designed as topresent a multiple of the inner surface radiated by the flames. Thissurface enlargement is accomplished, for instance, by means of bolts orribs arranged in the flow direction of the coolant. So that the innerjacket can expand in all directions under the influence of heat, itoften consists of single, identical components suspended from thesupport. Such components thus become readily exchangeable liner bodiesfor combustion chambers, various manufacturing methods for which areknown, but which are also afflicted with various disadvantages; forexample:

a. Cast liner bodies. Spacing and thickness of the cooling elements,especially when designed as cooling fins, become big when this method isused so that the surface enlargement of the side to be cooled isdetracted from.

b. Extrusion, with suspension hooks welded on subsequently. Logically,the disadvantages are the same as those listed under (a). But add tothis that only the same profile can be extruded, but no interruptions orbolts, for instance. Furthermore, the wear of the very expensive toolsis great, and the required welding on of the hooks has not proven outwell. I

c. Milling from the solid, with subsequent welding on of the suspensionhooks. Material expense and tool wear are too great for economicalproduction. Disadvantage of the welded-on hooks as under (b).

. Fusing a cover plate onto the cooling elements. It has turned out thatthe plate placed on top of the cooling elements does not fuse uniformlyso that the cooling elements are not joined to the plate uniformly,particularly not cooling fins over their entire length. This impairs theheat conduction between the plate and the cooling elements.

SUMMARY OF THE INVENTION The present invention is based on the task ofproducing economically, and avoiding the disadvantages inherent in theknown methods, a liner body which, to the greatest possible extent,meets the conditions required for a good heat transfer on the cooledside and assures a reliable connection between the cooling elements ofany shape and the cover plate. According to the invention, this problemis solved in that the cover plate, including one end of the coolingelements which are held in their correct position, is made completely ofwelding material.

The drawing illustrates exemplarily a liner body made by the methodaccording to the invention,

FIG. 1 showing a cross-section of the body with a part of the holdingdevice, and

FIG. 2 a portionfrom the side view of the liner body.

The cooling fins 1 are inserted into the holding device 2, and theirupper ends protrude into the cover plate 3. The two somewhat stronger,outer cooling fins are equipped with a suspension hook 4, and theirupper ends are bent outward so that they form a part of the limitingedges of cover plate 3. These edges abut the adjacent liner bodies afterassembly in the combustion chamber.

Another design possibility for the two outer cooling fins consists inleaving their upper ends parallel to the other cooling fins and bendingthem inward in S-shape so that they again form a limiting edge of thecover plate, their upper portion abutting, after assembly, the coolingfin, which is symmetrical thereto, of the adjacent liner body. For therest, due to their S-shape, they leave a free space between each otherfor the coolant.

To produce the liner body, the cooling elements such as fins, ribs orbolts are inserted into the template-like holding device, thereby beingfixed in their correct position already which they will assume later inthe finished liner body. The cooling elements protrude out of theholding device only as much as will be included in the cover plate bythe subsequent welding operation. This concludes the preparatory work,and the cover plate can be manufactured. This is done by build-upwelding and the use of additional wire or additional strip, by layingone bead next to the other over the width of the liner body. In general,one welding layer suffices, but more of them can be put on top of eachother, of course. It has proved to be expedient, when using coolingfins, to weld transversely across them because welding in longitudinaldirection will reduce the strength of the finished body. If a secondwelding layer is applied, it may be put on in longitudinal direction.During the welding operation, the arc burns directly on the ends of thecooling elements protruding from the holding device, thereby effectingtheir complete connection with the welding material.

Using this manufacturing method, one is at liberty to select or combinethe materials at will. Cooling elements and welding material may be ofthe same material, but it may also be advantageous to select a highlyheat resistant material for the side facing of the combustion area, thatis the welding material for the cover plate, and to use a material ofgood heat conductivity for the cooled side, that is for the coolingelements.

To prevent the surface of the holding device in contact with the coverplate from being welded also during the welding operation, it sufficesto select for the holding device a material of good heat conductiveproperties, such as copper. In addition thereto, or also as a singularmeasure, the holding device: may be cooled, too, for instance when theheat conductivity of the holding device is not or only slightly betterthan that of the cooling elements.

The method described is suited particularly for the economic productionof greater numbers. In comparison to the above mentioned previouslyknown production methods, costs are reduced considerably, and noparticular demands are made on the operating personnel of the weldingequipment. A good connection between cover plate and cooling elementsand,

hence, a reliable dissipation of the heat=from the cover plate isassured, and the supersonic inspection, hitherto required over eachindividual cooling element, is obviated.

lclaim:

l. A method for manufacturing liner bodies for combustion furnaces, saidliner bodies having cooling elements on the outer surface thereofcomprising placing a plurality of cooling elements in spaced parallelrelation in a template-like holding device, said holding devicepositioning said cooling elements in the same relative position as inthe finished liner bodies, portions of adjacent edges of the coolingelements extending beyond the edge of the holding device, depositing atleast one layer of welding material transversely to the portions of thecooling elements which extend beyond the holding device and applyingsame in such an amount as to surround and cover the extended portions ofthe cooling elements and effect fusion of the welding material to theextended portions of the cooling elements to integrally unite thewelding material to the extended portions and also form a cover surfaceof welding material on the inner surface of the liner body and finallyremoving the liner body from the holding device.

2. A method as claimed in claim 1 wherein the cooling elements arecomposed of the same welding material as is applied to the portions ofthe cooling elements extending beyond the holding device.

3. A method as claimed in claim 1 wherein the cooling elements arecomposed of a material having good heat conductivity and wherein thewelding material applied to the portions of the cooling elementsextending beyond the holding device is a high heat resistant weldingmaterial.

4. A method as claimed in claim 1 and further comprising applying asecond layer of welding material onto the transverse layer thereof in adirection longitudinal of said cooling elements.

5. A method as claimed in claim 1 and further comprising cooling theholding device during the application of the welding material.

1. A method for manufacturing liner bodies for combustion furnaces, saidliner bodies having cooling elements on the outer surface thereofcomprising placing a plurality of cooling elemEnts in spaced parallelrelation in a template-like holding device, said holding devicepositioning said cooling elements in the same relative position as inthe finished liner bodies, portions of adjacent edges of the coolingelements extending beyond the edge of the holding device, depositing atleast one layer of welding material transversely to the portions of thecooling elements which extend beyond the holding device and applyingsame in such an amount as to surround and cover the extended portions ofthe cooling elements and effect fusion of the welding material to theextended portions of the cooling elements to integrally unite thewelding material to the extended portions and also form a cover surfaceof welding material on the inner surface of the liner body and finallyremoving the liner body from the holding device.
 2. A method as claimedin claim 1 wherein the cooling elements are composed of the same weldingmaterial as is applied to the portions of the cooling elements extendingbeyond the holding device.
 3. A method as claimed in claim 1 wherein thecooling elements are composed of a material having good heatconductivity and wherein the welding material applied to the portions ofthe cooling elements extending beyond the holding device is a high heatresistant welding material.
 4. A method as claimed in claim 1 andfurther comprising applying a second layer of welding material onto thetransverse layer thereof in a direction longitudinal of said coolingelements.
 5. A method as claimed in claim 1 and further comprisingcooling the holding device during the application of the weldingmaterial.